Tools for measuring the height of a valve relative to a reference plane or surface are sometimes used to determine how far a valve has recessed into a cylinder head. The amount of recession may be an indication of cylinder head life, so that the cylinder head can be replaced before a damaging failure occurs.
Such tools may be referred to as valve height measuring tools or valve recession measuring tools. Typically, an initial measurement will be taken to determine the relative distance between a point on the valve in the cylinder head and another surface. For a number of valve head configurations, known existing tools require that the cylinder head cover and valve rocker arms be removed to expose the valves and to expose a surface of the cylinder head upon which the tool may be placed. Measurements will be taken at periodic intervals, and the difference between the measurements represents valve recession. Each time a measurement is taken, the cylinder head covers and the valve rocker arm assemblies must be removed. In addition to the time required to remove the rocker arms, time must be spent readjusting the rocker arms, which occurs each time the rocker arms are removed and replaced.